The technical field of this invention is material analysis and, in particular, the invention relates to the detection and quantification of analytes in materials by measuring infrared absorptivity at multiple wavelengths.
Material analysis, especially the analysis of liquid materials for the presence of solutes, can be a tedious and complex task. In many instances, it would be more desirable to be able to analyze materials quickly, easily and non-invasively. One example of such an application is blood analysis.
Treatment of many medical disorders, particularly vascular conditions, can require accurate blood analysis. Additionally, in some situations, repeated or even continuous blood monitoring is desirable, for example, when monitoring cholesterol level variations.
Conventionally, blood is analyzed by withdrawing a sample from the body of a subject and examining it, using one or more techniques, such as immunoassays, activity assays, chromatographic assays and spectrophotometric assays. These conventional methods suffer from several common disadvantages. One such disadvantage is that these tests are invasive and raise the risk of patient infection and discomfort.
In addition, such tests can be time consuming. This time delay between when the blood is drawn and when the analysis is completed provides a window during which the subject's blood content may have changed, possibly leading to erroneous test results. A further disadvantage to conventional blood testing techniques is that the people drawing and testing the blood sample are put at risk for exposure to infectious disease agents.
Accordingly, it is the object of the present invention to provide an analytic apparatus for non-invasively, quickly and continuously detecting and quantifying cholesterol in a blood sample.
It is another object of this invention to provide a method and apparatus for non-invasive detection of blood-cholesterol levels but which avoids the problems of non-continuous test results, subject discomfort and potential technician exposure to infectious agents.